Method and Use of High Tension Cable Barrier Clamp

ABSTRACT

The present invention is a portable clamp to facilitate the construction and post-impact repair of high tension cable median barrier systems. Such a clamp allows a single operator to manipulate a high tension cable in order to install the hook bolts necessary to maintain proper function of the barrier system, thereby reducing the number of required employees and costs associated with the installation and repair processes.

BACKGROUND OF THE INVENTION

1. Field of The Invention

The present invention relates to high tension cable median barrier systems. More specifically, the present invention is an instrument that facilitates the repair of high tension cable median barrier systems.

2. Background Information

Cable barrier has been in use as a roadside barrier since the 1960's. In the 1980's, some state departments of transportation started using a modified cable rail as a median barrier. Today, many states, e.g., Texas, Missouri, Arizona, Colorado, North Carolina, Oklahoma, Ohio, Oregon, South Carolina, and Utah, are installing cable barrier in the medians of freeways originally built without barrier. In addition to the original “generic” low-tensioned design, there now exist competing proprietary high-tension designs that require less maintenance after a crash. According to the Spring 2006 issue of the Tech Transfer Newsletter, new data suggest that cable median barriers are an effective mechanism for preventing fatal and disabling crashes. However, high maintenance costs, both actual and in some cases, perceived, have limited its use.

Since 1989, the American Association of State Highway and Transportation Engineers (AASHTO) Roadside Design Guide has contained information on a cable median barrier design that mounts the middle cable on the back side of the posts so that it can contain and redirect vehicles that strike the system from either side.

The Washington State Cable Median Barrier In-Service Study was presented in November 2003 to the 83^(rd) Annual Meeting of the National Transportation Research Board, Washington D.C. The Study reported that the “societal benefit of cable median barrier was calculated to be $420,000 per mile annually” and that “given the societal benefits associated with the use of cable median barrier at locations having prior cross median accidents, cable median barrier has been found to be a cost effective solution to median crossover accidents.

Many organizations, entities or agencies responsible for the construction and maintenance of roads and highways utilize barrier systems for highway medians. One such barrier system is a high tension cable median barrier system. The primary advantage of providing these systems is the prevention of thousands of deaths and serious bodily injuries each year due to motor vehicle collisions involving vehicles that have collided with oncoming vehicles driving on the opposite side of the highway. By deflecting the vehicles headed toward the median, the vehicles are brought to a stop before they can create a hazardous situation for drivers on the opposite side of the highway.

High tension cable median barrier systems, which can sustain hits and still remain effective, consist of three high tension steel cables strung across and attached to steel anchoring posts. The posts are placed approximately at six feet intervals. Cables are run adjacent to the steel posts.

Special tools are required to stretch the cables to their optimum performance value of over 5,000 pounds of tension. The cables must then be attached to the posts, at approximately a four inch vertical interval, using special locking hook bolts. To mount the cable into the bolts, the cable must be raised up beyond its natural height and inserted into the hook portion of the bolt, and then the bolt must be secured into the post. Currently, the practice of mounting the cables onto the hook bolts of each post requires three individuals to complete. Typically, two individuals are required to hold up the cable which is stretched to over 5,000 pounds of tension and difficult to manage. Once the cable is lifted high enough, the third individual must then insert the cable into the hook and secure the hook bolt onto the post. This process must be followed each time there is an impact to the system, since each impact necessitates repair.

Upon impact, the anchoring posts are designed to break away from the ground. The high tension cables absorb the vehicle's impacting force and prevent it from continuing across the median into incoming traffic. After an impact, those responsible for maintaining the highway must immediately repair the barrier system. First, the damage posts are removed, and new posts are inserted in sockets. Then, the process of securing the cables to the posts must be completed again, as described above. The repair is virtually impossible for one person. All three individuals must be present and coordinate with each other to complete the repair.

In view of the above, it would well serve those entities responsible for maintaining high tension cable median barrier systems to utilize an instrument to best facilitate the repair process. Providing such a device would reduce the number of employees required to repair the cable system, reduce the currently required man-hours for such repairs, and therefore reduce the costs associated in the repair process. If the device allowed one person to attach the cables to the posts without the assistance of the other two, the entity responsible for maintaining the system could potentially save up to or exceed 66% of the cost of the repair.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention to provide an instrument to facilitate the initial installation and repair process of high tension cable median barrier systems after an impact.

It is another object of the present invention to provide an instrument that can be easily transported to a repair site, and used by a single operator to manipulate the cable and install the hook bolts.

It is another object of the present invention to drastically reduce the number of employees required for the repair process, and thereby reduce the costs associated with the repair process.

In satisfaction of these and related objects, the present invention is an instrument that facilitates the repair of high tension cable median barrier systems after an impact.

The present invention is a portable clamp that allows a single operator to manipulate the cable, install the hook bolts, and mount the cable to said bolts. The present invention affords a cost-reducing method of installing and repairing high tension cable barrier systems by reducing the required number of employees from three to one in the installation and repair processes.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a side view of the preferred embodiment of the high tension cable clamp of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a preferred embodiment of a high tension cable clamp of the present invention is identified generally by the reference numeral 1.

Clamp 1 includes frame 5 (“support assembly”), constructed in any suitable manner, as to comprise a generally “C” shape with end portions 9 and 10. End 9 is an anvil that directly opposes end 10. Square tubing 8 (“first cable engagement means”) is mounted perpendicularly to anvil 9, such that the opening of square tubing 8 (“first cable engagement means”) faces the opening of square tubing 7 (“second cable engagement means”). End 10 contains a threaded opening through which threaded rod 4 (“contraction means”) passes. End 11 of threaded rod 4 (“contraction means”) has an unthreaded bore through which an L-shaped rod 3 passes and acts as a torque bar for the purposes of manipulating threaded rod 4 (“contraction means”). L-shaped rod 3 also has an end 14, which is larger than the unthreaded bore at end 11. End 14 does not allow rod 3 to be completely removed from end 11. A nut and washer configuration 15 attaches to end 12 of L-shaped rod 3 and allows gripping wheel 2 to freely spin so as to allow the user of the present invention to apply torque to or remove torque from threaded rod 4 (“contraction means”) without releasing his grip in the process. Attached to end 13 of threaded rod 4 (“contraction means”) is pipe 6. Pipe 6 connects threaded rod 4 (“contraction means”) and square tubing 7 (“second cable engagement means”) such that square tubing 7 (“second cable engagement means”) may spin freely, for the purpose of maintaining controlled pressure on a cable while the user decreases the distance between square tubing 8 and square tubing 7 (“second cable engagement means”) by applying torque to threaded rod 4 (“contraction means”) in the proper direction. Square tubing 7 (“second cable engagement means”), as described above, is attached to pipe 6 in a manner that allows square tubing 7 (“second cable engagement means”) to spin.

It should be noted that, while steel is used to construct clamp 5 (“support assembly”), pipe 6, and threaded rod 4 (“contraction means”), plastic is used to construct gripping wheel 2, and steel is also used to construct rod 3, square tubing 7 (“second cable engagement means”) and square tubing 8 (“first cable engagement means”), and are presently believed to be the optimal materials for their respective purposes, other resilient materials may be substituted. In some cases, however, performance will not be optimal, as is presently observed with the materials as they are used in the present invention, and economics of some alternative approaches may outweigh the benefits enjoyed through practice of the present invention.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention. 

1. A system for repair or construction of cable-based roadside barriers systems comprising: a first cable engagement means, configured for reversibly engaging a length of a first cable of a cable-based roadside barrier; a second cable engagement means, configured for reversibly engaging a length of a second cable of a cable-based roadside barrier; a support assembly, said first cable engagement means being interfaced with said support assembly and oriented for reversibly engaging with said length of a first cable of a cable-based roadside barrier; said second cable engagement means being moveably interfaced with said support assembly and oriented for reversibly engaging with said length of a second cable of a cable-based roadside barrier; contraction means, interfaced with said second cable engagement means, for selectively moving said second cable engagement means relative to said support assembly whereby, when said first cable engagement means is engaged with a length of a first cable of a cable-based roadside barrier, and said second cable engagement means is engaged with said length of a second cable of a cable-based roadside barrier, said contraction means, upon actuation, moves one or both of said cables relative to each other.
 2. The system of claim 1 wherein said contraction means comprises complimentary threads between an interface means of said second cable engagement means and said support assembly, whereby rotation of said interface means effects a linear motion of said second cable engagement means relative to said support assembly and changes the distance between said second cable engagement means and said first cable engagement means.
 3. The system of claim 1 wherein said contraction means comprises complimentary ratchet components between an interface means of said second cable engagement means and said support assembly, whereby actuation of said ratchet components effects a substantially linear motion of said second cable engagement means relative to said support assembly and changes the distance between said second cable engagement means and said first cable engagement means.
 4. A method for repair or construction of cable-based roadside barriers systems comprising the steps of: selecting a system for repair or construction of a cable-based roadside barrier system, itself comprising: a first cable engagement means, configured for reversibly engaging a length of a first cable of a cable-based roadside barrier; a second cable engagement means, configured for reversibly engaging a length of a second cable of a cable-based roadside barrier; a support assembly, said first cable engagement means being interfaced with said support assembly and oriented for reversibly engaging with said length of a first cable of a cable-based roadside barrier; said second cable engagement means being moveably interfaced with said support assembly and oriented for reversibly engaging with said length of a second cable of a cable-based roadside barrier; contraction means, interfaced with said second cable engagement means, for selectively moving said second cable engagement means relative to said support assembly whereby, when said first cable engagement means is engaged with a length of a first cable of a cable-based roadside barrier, and said second cable engagement means is engaged with said length of a second cable of a cable-based roadside barrier, said contraction means, upon actuation, moves one or both of said cables relative to each other; engaging said first cable engagement means with a length of a first cable of a cable-based roadside barrier; engaging said second cable engagement means with a length of a second cable of a cable-based roadside barrier; actuating said contraction means for effecting a change in the relative distance between respective said lengths of said first and said second cables.
 5. The system of claim 4 wherein said contraction means comprises complimentary threads between an interface means of said second cable engagement means and said support assembly, whereby rotation of said interface means effects a linear motion of said second cable engagement means relative to said support assembly and changes the distance between said second cable engagement means and said first cable engagement means.
 6. The system of claim 4 wherein said contraction means comprises complimentary ratchet components between an interface means of said second cable engagement means and said support assembly, whereby actuation of said ratchet components effects a substantially linear motion of said second cable engagement means relative to said support assembly and changes the distance between said second cable engagement means and said first cable engagement means. 